As semiconductor wafer fabrication evolves, element geometries become smaller, which provide greater densities that drive down costs, decrease device sizes, increase functionalities, enable increasing levels of integration, or any combination thereof. Certain applications require both bipolar and field effect transistor (FET) elements. Integration of bipolar transistors and FETs onto a single substrate may enable the realization of circuits and products with reduced size, cost, complexity, and improved performance. Thus, there is a need to integrate bipolar transistor elements and FET elements onto a common substrate.